ACCRA, May 29 (Reuters) - Youths in the Central African Republic set up barricades on roads in the capital on Thursday and lit fires in protest at an attack by Muslim gunmen on a church that left at least 11 people dead, witnesses said.

Gunmen sprayed bullets and hurled grenades at people sheltering at the Our Lady of Fatima church on Wednesday following a battle between anti-balaka Christian militia and residents of the nearby Muslim neighbourhood of PK5.

Peacekeepers from France and the African Union were working to remove the barricades, said Francis Che, head of communications for the African Union peacekeeping force MISCA.

"People need to understand that we will crack down on them and bring them before national or international justice. We will have zero tolerance for the authors of this kind of act," Che told Reuters in reference to the church attack. (Reporting by Matthew Mpoke Bigg; Editing by Alison Williams)